The graph below is called a heating curve. it shows how water changes from one state of matter to another based on temperature and the addition or removal of heat over time. at which point on the graph would water be entirely gas?

Explanation :

The heating curve shows how water changes from one state of matter to another based on temperature and the addition or removal of heat over time.

Initially, ice is heated until its temperature reaches and changes to liquid state.

From the attached graph it is clear that until the temperature will rise steadily. Here, the liquid begins to vaporize. Vaporization is the state of matter at which liquid state changes to the gaseous state.

So, E is the point which shows the gaseous state.